Overly Stringent Criteria for COVID-19 Testing Led to Missed Diagnoses

Dawn O'Shea

June 21, 2021

Overly stringent criteria for SARS-CoV-2 testing early in the pandemic led to missed diagnoses of COVID-19, say researchers at the University of Nottingham.

The team screened 1660 diagnostic specimens which had been collected at Nottingham University Hospitals between 2 January 2020 and 11 March 2020 and tested by polymerase chain reaction (PCR).

In addition, they screened available archival specimens submitted for respiratory virus diagnosis, and dating back to early January 2020, for the presence of SARS-CoV-2 RNA.

With a shortage of tests at that time, strict criteria were required in order to qualify for testing, including contact with an infected individual or travel to a high-risk area.

The data showed that, prior to the roll out of localised SARS-CoV-2 testing on 12 March 2020, nine cases matching the case definition at the time were identified and referred to PHE for testing.

Of 1660 samples, three SARS-CoV-2 positive samples were identified through retrospective PCR screening.

  1. 75-year-old female admitted after a fall who had respiratory failure. The patient died on 3 March 2020. She did not meet the requirements for testing.

  2. 64-year-old male with suspected liver abscess, presenting with repeated fevers and crackles but there were no abnormalities on chest X-ray.

  3. 66-year-old male admitted with a sore throat and symptoms of Guillain-Barre syndrome, with mild abnormalities on chest X-ray.

Commenting on the findings, the authors say testing should have been made available to hospital patients with compatible symptoms earlier in the pandemic.

"It is likely that the true prevalence of the virus within the local study setting and indeed the wider UK during the timeframe of this study was much higher than we have reported here, particularly from early-February onwards, as our study was limited to symptomatic individuals requiring secondary medical care. Asymptomatically infected individuals, along with those presenting with mild or paucisymptomatic infection, are likely to comprise a significant proportion of the total number of infections," they add.

"The salient finding from our study is that simple opportunities to identify early cases of SARS-CoV-2 infection were missed due to overly stringent case-criteria. Had the diagnostic criteria been widened earlier to include patients with compatible symptoms but no travel history, it is likely that earlier imported infections would have been detected, enabling rapid deployment of infection control measures that may have prevented onwards transmission."

They say the UK urgently needs to invest in and expand diagnostic capacity for future pandemic preparedness.

J Gen Virol. Published online June 16, 2021. Full text

References: Chappell JG, Tsoleridis T, Clark G, Berry L, Holmes N, Moore C, Carlile M, Sang F, Debebe BJ, Wright V, Irving WL, Thomson BJ, Boswell TCJ, Willingham I, Joseph A, Smith W, Khakh M, Fleming VM, Lister MM, Howson-Wells HC, Holmes EC, Loose MW, Ball JK, McClure CP; On Behalf Of The Cog-Uk Consortium. Retrospective screening of routine respiratory samples revealed undetected community transmission and missed intervention opportunities for SARS-CoV-2 in the United Kingdom. J Gen Virol. 2021;102(6). doi: 10.1099/jgv.0.001595. PMID: 34130773

This article originally appeared on Univadis, part of the Medscape Professional Network


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